Chemistry Consider a chromium-silver voltaic cell that is constructed such that one half-cell consists of the chromium, Cr, electrode immersed in a Cr(NO3)3 solution, and the other half-cell consists of the silver, Ag, electrode immersed in a AgNO3 solution. The two electrodes are ...
May 12, 2014

PhysicsSam, whose mass is 76kg , takes off across level snow on his jet-powered skis. The skis have a thrust of 220N and a coefficient of kinetic friction on snow of 0.1. Unfortunately, the skis run out of fuel after only 15s . How far has Sam traveled when he finally coasts to a stop?
May 11, 2014

Physics A wheel turns through 90.0 revolutions in 15.0 sec. The angular speed at the end of this 15.0 sec period is 10.0 rev/s. Assuming that the angular acceleration is constant, calculate a) the angular speed at the beginning of the 15.0 sec interval, and b) the amount of time that ...
May 5, 2014

Physics A catapult launches its payload at a 50.0degrees angle and the payload leaves the catapult 3.00 meters off the ground. If the payload travels 300.0 meters in the horizontal direction, what was the launch speed? At what speed does the payload hit the ground?
April 21, 2014

physics A screen is placed exactly one meter away from an illuminated test pattern. A lens placed between them forms a clear (focused) image of the pattern on the screen when the center of the lens is 200 mm from the test pattern. What is the focal length of the lens? ( cm)
November 10, 2011

physicsA 8.20 cm tall object is placed 30.0 cm in front of a concave mirror with a focal length of 4.20 cm. What is the magnification?
November 10, 2011

physics A coin 1.9 cm in diameter is held 40 cm from a concave spherical mirror of 30 cm radius of curvature. Locate the image of the coin Then what is the diameter of coin?
November 10, 2011

PhysicsThe stored electrical energy of a 800-Ê F capacitor charged to 1.20~104 Volts is converted to thermal energy by discharging the capacitor through a heating element submerged in 711.6 g of water in an insulating cup. What is the increase in temperature of the ...
September 22, 2011

PhysicsA parallel-plate capacitor is designed so that the plates can be pulled apart. The capacitor is initially charged to a potential difference of 80 Volts when the plates are 1.0 mm apart. The plates are insulated so that the charge cannot leak off. What is the potential ...
September 22, 2011

physicsA small droplet of oil with mass of 1.84×10-15 kg is held suspended in a region of uniform electric field directed upward with a magnitude of 6625 N/C. Is the excess charge on the droplet positive or negative? NEGATIVE b.How many excess elementary charges reside on the ...
September 1, 2011

physicsThree equal positive point charges of magnitude Q = 8.00ì C are located at three corners of a square of edge length d = 11.8 cm. A negative charge -24.00ì C is placed on the fourth corner. At the position of the negative charge, what is the magnitude of the ...
September 1, 2011

MathsThe question is "Show that z-2 is a factor of P(z)= z^3+mz^2+(3m-2)z-10m-4 for all values of m. For what values of m is (z-2)^2 a factor of P(z)?" I've proven the first part, using synthetic division, for all values of m. But the second part, I don't ...
April 13, 2009

ChemistryI just did an experiment on the enthalpy of combustion of different alcohols, and for my report, I've written that the condition of the wick is a source of random error, but i can't seem to explain it. I've written that it affects the rate of burning of the flame, ...
April 7, 2009

Maths - MatricesI'm having trouble with doing this matrix proof The question is "Given some matrix A has the property A*2=A^-1, show that determinant A = 1, i.e |A| = 1" I've tried for ages, but I can't seem to do it, this is what I got to A^2= A^-1 |A^2| = |A^-1| |A|^2...
March 29, 2009

PhysicsI'm writing a prac report, and I just need something clarified. The experiment was different masses were attached on a hanging spring, then it had to be pulled down a certain distance, then find the period by finding the time fo each oscillation for each mass. The problem ...
March 28, 2009

PhysicsI'm writing a prac report, and I just need something clarified. The experiment was different masses were attached on a hanging spring, then it had to be pulled down a certain distance, then find the period by finding the time fo each oscillation for each mass. The problem ...
March 28, 2009

PhysicsI'm writing a prac report on an experiment where we had to vary the mass on a spring, and graph it against the period, then graph it again when period vs square root of mass, which should be linear given the proportionality. Does it really matter which unit i use? g or kg
March 26, 2009

MathsCould someone help me with this question Write in polar form : sinx - i cosx I've come up to this point, and it's wrong, can't someone please help? =sin(pie/2-x)-icos(pie/2-x) =cosx-isinx =cis(-x) But the answer is cis(x-pie/2)
March 4, 2009

Maths - TrigI just had a test, and one question I tried heaps of times and I still couldn't answer. It was "Prove secèsinè + cosecè cosè = 2cosecè " Can someone please tell me if proving this is possible at all? (But don't tell me how ...
February 19, 2009

maths reciprocalJust out of curiousity, are you from Adelaide? Because I got this same assignment, which is from the SSABSA website. I just thought you were a friend of mine, because my friend also uses the initials TK< but he didnt post this.
August 24, 2008

Maths - ReciprocalsI'm having some troubles. I can't think of an example to this question. Give an exmaple of a quadratic whose reciprocal has no vertical asymptotes I think it's 1/x^2. The question says vertical asymptotes so I'm assuming they mean there will only be one. But I ...
August 24, 2008

Chemistry - NeutralisationI'm having a few troubles on my equations. I have to write the neutralisation reaction equation between Acetic Acid and Sodium Hydrogen Carbonate I've gotten this far, but I don't if its the right way to do it CH3COOH + NaHCO3 ---->>> (salt) + H2O I dont ...
August 21, 2008

English - MacbethI think I get the idea of a tragic hero, but for my essay, should I have a point in there somewhere to argue how he is a tragic monster and not a monster, because the question asks "Is Macbeth a tragic hero.....or a monster?"
August 17, 2008

English - MacbethI have a little trouble understanding my essay question. This question is: Is Macbeth a tragic hero according to the classical definition of the term or is he merely a monster? Does Shakespeare succeed in creating sympathy for Macbeth? To repsond to this question in an essay, ...
August 17, 2008

EnglishI just had an English exam, and I don't think I do too well. Anyways, there was a few questions in it that I didn't quite understand in the prose questions (comprehensions or whatever they're called). After reading the passage, there was a question asking "...
June 10, 2008

EnglishI've got a few sentence here, but I always get confused whether to use affect or effect. Can you help me out? 1. Furthermore, Lee and Hosseini illustrate the affect that the experiences their protagonists encounter during childhood have upon the characters as adults. 2. ...
June 4, 2008

Real Estate Project (Maths)I don't know if you can help me here or not, but I'll ask anyways. I've been given a Real Estate assignment where I had to compare the sale prices of properties of different suburbs and then compare them, with the Mean, Standard Deviations, Histograms, Boxplots, ...
May 31, 2008

Oral PresentationsI've got an upcoming speech to prepare, and my teacher has hardly given any preparation time and I'm the type of person who is very conservative and quiet. I'm afriad of being boring with my speech because our teacher has told us to make it interesting, and make it...
May 25, 2008

PhysicsI'm doing a report on my experiment right now where you had to test out the voltage and current of 2 resisters and a light globe with an ammeter and voltmeter. We had to graph the results, and the reisistors had a linear relationship between voltage and current, but the ...
May 24, 2008

Statistics - ExcelCan anyone help me with finding Standard Deviation in Excel? I have about 20 entries of different house prices, and I need to find the standard deviation. I know you had to enter something like 'SDEV=" but I can't remember.
May 24, 2008

PhysicsWhat are differences and similarities of the electric charges (+ and -) and the magnetic forces (North and South)?
May 19, 2008

EconomicsIs there a website to find the inflation rates of the America? I've tried to search on google, but I don't know their central bank is.
May 14, 2008

Source Analysisobviously they're typos, you don't need to critique my writing, if i wanted it to be perfect, i would have corrected it
May 7, 2008

Source AnalysisI have an upcoming source analysis for my mid year exam in Ancient History, and after my past few source anaylsis', I haven't had of the greatess success. If there any websites or guides that could help me anaylse sources, such as sections of text and pictures. The ...
May 7, 2008

EconomcisI have an assignment on the the factors which impact the Australian dollar. "How does the government influence the value of the Australian dollar?"
May 2, 2008

Physics - Light & refractionI go this question in a test just today, but I know I got it wrong because I didn't study this section. It was something along the lines of this I'm pretty sure. "Explain why there is no critical angle when light travels from air to water" Can someone explain...
May 2, 2008

MathsThe weight of a termite mound (y) in kilograms is measured each month (x) after it was first found. The mound after 1 month is found to be 2 kilograms and after 3 months it is measured at 18 kilograms. It is believed that the model connecting the weight of the mound to the ...
April 14, 2008

English - Connected TextsIs Romeo and Juliet a book that has a lot of complex themes or messages? I haven't read it personally, but I just want to make sure I'm not in-over-my-head because I have two weeks of holidays to read the book, and watch a film and write a 5 page journal for each text...
April 11, 2008

English - Connected TextsWell actually, I could do a book and film. Its better if I do a novel and film because it will prepare me better for the following year, so if you have a book & film or film & film that you can suggest, it would be very helpful.
April 11, 2008

English - Connected TextsCan anyone suggest two films that I could use to compare and contrast? Because I have to choose two for my English task, and the films have to a decent amount of smiliarites. My problem is that there are too many movies out there to choose from and I'm not good at making ...
April 11, 2008

Ancient HistoryIt was Sparta, not Athens which won the war against Persia. To what extent is this view of the Persian War correct? I've decided that it the statement is patly correct. Is there any websites/study guides/free essays that could help me with ideas for writing the...
March 31, 2008

English - Critique Essay PleaseThis is how much I've done so far, not finished yet but could you see if I'm on the right track? I'm following the structure of Introduction, 3 Main Body Paragraphs and a Conclusion. Explain how the themes of prejudice and tolerance are explored in the novel. The ...
March 26, 2008

English - Essay WritingI've just read the book 'To Kill a Mockingbird and I have to write an essay on the question "Explain how the themes of prejudice and tolerance are explored in the novel" I've started on my essay, but it's been a long time since I've written one. I...
March 25, 2008

PhysicsHow can you use a curved mirror to make a telescope? If possible, if there a diagram somewhere?
March 25, 2008